How Long Can a Car Battery Sit Unused and Still Work?

[Aubrey]

Car batteries can typically sit unused for 15 to 30 days and still function, but most won't be able to start the car if left unused for over 30 days. Car batteries, also known as storage batteries, are a type of battery that works by converting chemical energy into electrical energy. There are several types of car batteries: conventional lead-acid batteries, dry-charged batteries, and maintenance-free batteries. Generally, when people refer to car batteries, they mean lead-acid batteries. Conventional batteries have plates made of lead and lead oxide, with an electrolyte solution of sulfuric acid. Dry-charged batteries, short for dry-charged lead-acid batteries, are characterized by their negative plates' high energy storage capacity. They can retain their charge for up to two years in a completely dry state and only require the addition of electrolyte when put into use. Maintenance-free batteries are known for their resistance to vibration and high temperatures, compact size, and low self-discharge rate.